No mouse sensitivity option. I could look into that and see if I can figure it out. Honestly never occurred to me!
And no auto-explore per se. You can click any square to move there. You can also use a few keyboard shortcuts (Ctl-g to move to the nearest treasure, Ctl-t to move to the temple, Ctl-s to move to stairs (unless I'm misremembering)). The problem with auto-explore in this game vs. other roguelikes, is that every 2 steps or so is going to reveal something you may want to interact with. It's not just a random space filled with monsters, it's filled with more than 500 different types of interactable squares. So auto-explore would either have to ignore those things, wasting the player's time in coming back to them (and time is not on your side in this game), or it would have to interrupt the auto-movement constantly anyway.